NET/MASTER Network Control Language (NCL) Programmer's Guide

Displaying a Panel
Working With Panels
14–58 106160 Tandem Computers Incorporated
The Cursor Positioning
Hierarchy
Where you can position the cursor depends on the type of terminal on which the panel
is being displayed. If the terminal is an IBM 3270 or compatible, you can position the
cursor at any input field or at any screen location. If the terminal is a Tandem 6530 or
compatible, you can position the cursor at any input (unprotected) field.
Panel Services uses the following steps to determine the position at which to place the
cursor when a panel is displayed:
1. If internal validation detects an error, the cursor is positioned on the first field in
error.
2. If a field is identified as being in error by the #OPT ERRFLD statement, the cursor
is positioned on the field in error.
3. If a field is set as being in error by the ASSIGN SETERR verb, the cursor is
positioned on the field in error. Any field set by the ASSIGN SETERR verb that is
also identified by the #OPT ERRFLD statement takes precedence.
4. The cursor is positioned on the location identified by the #OPT CURSOR
statement.
5. The cursor is positioned on the first input field, detected by scanning from top to
bottom and left to right.
6. If there are no input fields on a panel and the terminal is:
A 3270 or compatible, the cursor is positioned at the upper left corner of the
panel (row 1, column 1 of the window).
A 6530 or compatible, the cursor is not displayed.
Controlling Display
Duration
By default, whenever a synchronous or asynchronous panel is displayed, Panel
Services waits for input indefinitely. You can override this, but only for synchronous
panels, by using the INWAIT operand of the #OPT panel control statement. (INWAIT
is ignored for asynchronous panels.)
The INWAIT operand lets you specify an interval (in seconds or parts of seconds) for
Panel Services to wait for input. During this interval, standard keyboard entry is
accepted and processed normally. Once the time interval expires, control returns to
the invoking NCL process.
No visual indication is given when the time interval elapses. However, input is
ignored until another PANEL verb is executed. To give a visual indication, the NCL
process should display another panel or execute the PANELEND verb. The INWAIT
operand can also be used to display a series of panels that are updated periodically.
You can use this option to reduce the possibility of screen burnout if a panel displays
many high-intensity fields for long periods. You can use the INWAIT operand to force
a return of control after 20 minutes: for example, when a blank panel replaces the
display panel. The original panel can be redisplayed once suitable input is received.
If you specify INWAIT=0, keyboard entry is not accepted and control returns to the
NCL process after the panel is displayed. If required, the NCL process can then
perform its own delay: for example, using the DELAY verb.